CN1855368A - A Method for Manufacturing Field Emitters Using Laser-Induced Recrystallization - Google Patents

Abstract

A method for manufacturing a field emitter using laser induced recrystallization. According to the present invention, a substrate is provided on which a silicon-containing layer is formed. Laser induced recrystallization is then used to form a plurality of protruding tips protruding from the surface of the silicon-containing layer. The laser induced recrystallization method includes the step of subjecting all or part of the silicon-containing layer to an unpatterned or patterned energy source.

Description

A Method for Manufacturing Field Emitters Using Laser-Induced Recrystallization

technical field

This invention relates generally to semiconductor processing and, more particularly, to methods of fabricating field emitters using laser-induced recrystallization.

Background technique

In recent years, field emitters have been developed and widely used in the following electronic applications: field emission displays (FED), backlight units, field emission transistors, and field emission diodes. When subjected to an appropriate electric field, these field emitters emit electrons, which strike a phosphor coated on the backside of the transparent cover to generate an image or light. This type of cathodoluminescence is known as one of the most effective lighting methods. Generally, these field emitters can be designed using arrays consisting of multiple microtips or multiple carbon nanotubes.

Early field emitter developments used the so-called Spindt tip process to form metal microtips. In this process, a silicon wafer is first oxidized to create a thick silicon oxide layer, and a metal gate layer is then deposited on top of this oxide. The metal gate layer is then patterned to form gate openings, while a subsequent etch of the silicon oxide below the openings undercuts the gate and creates a well. A layer of sacrificial material, such as nickel, is deposited to prevent nickel from depositing in the silo. Molybdenum is then deposited at normal incidence so that a cone with a sharp point grows within the cavity until the opening is closed thereon. When this nickel sacrificial layer is removed, an emitter cone remains.

In an alternative design, silicon microtip emitters can be formed by first performing thermal oxidation on the silicon, then patterning the oxide and selectively etching to form the silicon microtips.

However, the main disadvantage of the microtip emitter is that complex processing steps have to be used to fabricate the device. For example, the formation of the various layers in the device, especially the formation of the microtips, requires thin film deposition techniques followed by photolithography and etching processes. Various process steps must therefore be performed in order to define and fabricate these various structural feature patterns. The film deposition process, photolithography process, and etching process involved will greatly increase its manufacturing cost.

It is therefore an object of the present invention to provide a method of manufacturing field emitters using laser-induced recrystallization which does not have the disadvantages or disadvantages of conventional methods.

Another object of the present invention is to provide a simple and cost-effective method for manufacturing field emitters using laser crystallization technology.

Contents of the invention

The present invention relates to a method of manufacturing a field emitter which obviates the problems caused by limitations and disadvantages of the known technology.

According to a specific embodiment of the present invention, it provides a method for manufacturing a field emitter, which includes the following steps: (a) providing a substrate; (b) forming a silicon-containing layer above the substrate; and (c) by allowing the The silicon-containing layer is subjected to an energy source to form a plurality of protruding tips protruding from the surface of the silicon-containing layer.

In addition, according to the present invention, it also provides a method for manufacturing a field emitter, which includes the following steps: (a) providing a substrate; (b) forming a silicon-containing layer on the substrate; A layer is subjected to a patterned energy source to form a plurality of protruding tips protruding from the surface of the silicon-containing layer.

Further, according to the present invention, it provides a method of manufacturing a field emitter, which includes the following steps: (a) providing a substrate; (b) forming a first conductor layer on the substrate; (c) forming a first conductor layer on the first conductor forming a silicon-containing layer over the silicon-containing layer; (d) sequentially forming an insulating layer and a second conductor layer over the silicon-containing layer; (e) patterning the second conductor layer and the insulating layer to expose the silicon-containing layer; and (f) Exposing the exposed silicon-containing layer to an energy source to form a plurality of protruding tips protruding from the surface of the exposed silicon-containing layer.

Furthermore, according to the present invention, it provides a method of manufacturing a field emitter, which includes the following steps: (a) providing a substrate; (b) forming a silicon-containing layer on the substrate; (c) patterning the silicon-containing layer a layer for forming a plurality of silicon-containing islands; and (d) exposing the silicon-containing islands to an energy source for forming a plurality of protruding tips protruding from the surfaces of the silicon-containing islands.

Additional features and advantages of the invention will be set forth in part in the description which follows, and in part will be apparent from the description, or may be learned by practice of the invention. The features and advantages of the invention will be realized and attained by means of the elements and combinations particularly pointed out in the appended claims.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention as claimed.

The drawings cited in this specification and constituting a part thereof are used to illustrate one specific embodiment of the present invention, and can be used to explain the principles of the present invention in conjunction with the description.

Description of drawings

Reference will now be made in detail to embodiments of the invention, an example of which is illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts.

Figure 1 is a schematic diagram of the formation of these protruding tips after a silicon layer has been exposed to a laser beam and then crystallized.

Figure 2 is a scanning electron micrograph of a protruding tip constructed using laser-induced crystallization in accordance with the present invention.

3A and 3B are schematic cross-sectional views of processing steps for fabricating a triode device according to a preferred embodiment of the present invention.

4A and 4B are schematic cross-sectional views of processing steps for fabricating a triode device according to another preferred embodiment of the present invention.

5A and 5B are schematic cross-sectional views of processing steps for fabricating a triode device according to a further preferred embodiment of the present invention.

6A and 6B are schematic cross-sectional views of processing steps for fabricating a triode device according to a further preferred embodiment of the present invention.

Description of main component marking

10 Substrate

11 Silicon-containing layer

12A grain

12B grain

14 liquid

16 Protruding tip

18 Grain boundary

300 openings

310 Protruding tip

30 base plate

31 Cathode electrode layer

32 energy source

33 Silicon-containing layer

34 Insulation layer

35 Gate electrode layer

36 top substrate

37 Anode electrode layer

38 Phosphorescent layer

39 Electronics

400 openings

410 Protruding tip

40 base plate

41 Cathode electrode layer

42 energy source

43 Silicon-containing layer

44 insulation layer

45 Gate electrode layer

46 top substrate

47 Anode electrode layer

48 Phosphorescent layer

49 Electronics

500 openings

510 Protruding tip

50 base plate

51 Cathode electrode layer

52 energy source

53 Silicon-containing layer

54 Insulation layer

55 Gate electrode layer

56 top substrate

57 Anode electrode layer

58 Phosphorescent layer

59 Electronics

600 opening

610 Protruding tip

60 base plate

61 Cathode electrode layer

62 energy source

63A Silicon island

63B Silicon island

64 Insulation layer

65 Gate electrode layer

66 top substrate

67 Anode electrode layer

68 Phosphorescent layer

69 Electronics

Detailed ways

Referring to FIG. 1, there is shown a schematic diagram for explaining that a silicon-containing layer is subjected to laser beam action and then crystallized to form a plurality of protruding tips. In FIG. 1, a silicon-containing layer 11 is deposited on a substrate 10, which may be one of several types of substrates. For example, the substrate 10 may be one of a silicon substrate, a glass substrate, a quartz substrate, a sapphire substrate, a plastic substrate, and the like. Preferably, the silicon-containing layer 11 is an amorphous silicon layer or a polysilicon layer. The silicon-containing layer 11 may be doped with n-type or p-type impurities. Preferably, the thickness of the silicon-containing layer 11 is between about 200 Ȧ and about 8000 Ȧ. Next, the silicon-containing layer 11 is exposed to an energy source (not shown in FIG. 1 ) and melts into a liquid 14 . Preferably, the energy source may be a laser beam, such as Nd:YAG laser, carbon dioxide (CO ₂ ) laser, argon (Ar) laser, excimer laser or similar lasers. At time t0, liquid 14 cools, causing certain portions 12A and 12B to nucleate and crystallize. Those skilled in the art generally refer to these solid portions 12A and 12B as "grains". These grains 12A and 12B will gradually extend from the liquid-solid interface (see time t1), and the liquid portion 14 will gradually protrude from this surface (see time t2), because liquid silicon (DLS) is denser than solid silicon ( DSS) density. Note that the gap between solid portions 12A and 12B becomes smaller and smaller over time. At time t3, the gaps between these solid portions 12A and 12B are closed, thereby forming grain boundaries 18 . At time t3, the liquid 14 disappears. However, protruding tips 16 are formed near the grain boundaries 18 and protrude from the surface of the silicon-containing layer 11 .

Referring to FIG. 2, shown is a scanning electron micrograph (SEM) image of a protruding tip formed by laser-induced crystallization according to the present invention. Figure 2 shows the silicon-containing layer 11 of Figure 1, which produces many protruding tips 16 after being acted on by an energy source, and these protruding tips can be applied to field emission displays, backlight units, field emission transistors or field emission Diodes are used as field emitters in applications.

Referring to FIGS. 3A and 3B , there are shown schematic cross-sectional schematic views of processing steps for fabricating a triode device according to a preferred embodiment of the present invention. As shown in FIG. 3A , in this embodiment, a cathode electrode layer 31 and a silicon-containing layer 33 are sequentially deposited on a base substrate 30 . As mentioned above, the base substrate 30 may be a silicon substrate, a glass substrate, a quartz substrate, a sapphire substrate, a plastic substrate or similar substrates. Preferably, the silicon-containing layer 33 is an amorphous silicon layer or a polysilicon layer doped with n-type or p-type impurities, and has a thickness ranging from about 200 Ȧ to about 8000 Ȧ. The entire silicon-containing layer 33 is then exposed to the energy source 32 and melted into a liquid. Preferably, the energy source may be a laser beam, such as Nd:YAG laser, carbon dioxide (CO ₂ ) laser, argon (Ar) laser, excimer laser or similar lasers. After being melted and crystallized, the silicon-containing layer 33 has a plurality of protruding tips 310 protruding from the surface of the silicon-containing layer 33 .

Next, an insulating layer 34 and a gate electrode layer 35 are sequentially deposited on the silicon-containing layer 33 , as shown in FIG. 3B . The insulating layer 34 and the gate electrode layer 35 are etched and patterned by etching and photolithography processes, thereby forming a plurality of openings 300 , exposing many parts of the silicon-containing layer 33 . Furthermore, an anode electrode layer 37 and a phosphor layer 38 are sequentially formed to cover the top substrate 36, which may be a silicon substrate, a glass substrate, a quartz substrate, a sapphire substrate, a plastic substrate, or similar substrates. The top substrate 36 is separated from the bottom substrate 30 by a predetermined distance, and will be placed together to form a complete triode device as shown in FIG. 3B . The triode-structured device utilizes the protruding tips 310 of the silicon-containing layer 33 as field emitters. When a voltage difference is applied between the cathode electrode layer 31 and the gate electrode layer 35 , electrons 39 are extracted from the cathode electrode layer 31 and accelerated toward the phosphor layer 38 .

Referring to FIGS. 4A and 4B , there are shown schematic cross-sectional schematic views of processing steps for manufacturing a triode device according to another preferred embodiment of the present invention. As shown in FIG. 4A, in this embodiment, a cathode electrode layer 41 and a silicon-containing layer 43 are sequentially deposited on a base substrate 40. The base substrate 40 may be a silicon substrate, a glass substrate, a quartz substrate, a sapphire substrate, a plastic substrate or similar substrate. Preferably, the silicon-containing layer 43 is an amorphous silicon layer or a polysilicon layer, which is doped with n-type or p-type impurities. Preferably, the thickness of the silicon-containing layer 43 is between about 200 Ȧ and about 8000 Ȧ. In this embodiment, portions of silicon-containing layer 43 are then exposed to patterned energy source 42 and melted into a liquid at predetermined locations. Preferably, an energy source 42 , such as a laser beam, is passed through a shutter or grating to generate the patterned energy source 42 . The energy source 42 may be one of the following: Nd:YAG laser, carbon dioxide (CO ₂ ) laser, argon (Ar) laser, and excimer laser. After being melted and crystallized, the silicon-containing layer 43 has a plurality of protruding tips 410 protruding from the surface of the silicon-containing layer 43 .

Next, an insulating layer 44 and a gate electrode layer 45 are sequentially deposited on the silicon-containing layer 43 , as shown in FIG. 4B . The insulating layer 44 and the gate electrode layer 45 are etched and patterned by etching and photolithography processes to form a plurality of openings 400 exposing the protruding tips 410 of the silicon-containing layer 43 . Furthermore, an anode electrode layer 47 and a phosphor layer 48 are sequentially formed to cover the top substrate 46, which may be a silicon substrate, a glass substrate, a quartz substrate, a sapphire substrate, a plastic substrate or similar substrates. The top substrate 46 is separated from the bottom substrate 40 by a predetermined distance, and will be placed together to form a complete triode device as shown in FIG. 4B . The triode-structured device utilizes the protruding tips 410 of the silicon-containing layer 43 as field emitters. When a voltage difference is applied between the cathode electrode layer 41 and the gate electrode layer 45 , electrons 49 are extracted from the cathode electrode layer 41 and accelerated toward the phosphor layer 48 .

Referring to FIGS. 5A and 5B , there are shown schematic cross-sectional schematic views of processing steps for manufacturing a triode device according to a further preferred embodiment of the present invention. As shown in FIG. 5A , in this embodiment, a cathode electrode layer 51 and a silicon-containing layer 53 are sequentially deposited on a base substrate 50 , which may be a silicon substrate, a glass substrate, a quartz substrate, a sapphire substrate or similar substrates. Preferably, the silicon-containing layer 53 is an amorphous silicon layer or a polysilicon layer doped with n-type or p-type impurities, and has a thickness ranging from about 200 Ȧ to about 8000 Ȧ. Next, an insulating layer 54 and a gate electrode layer 55 are sequentially deposited on the silicon-containing layer 53 . The insulating layer 54 and the gate electrode layer 55 are etched and patterned by etching and photolithography processes to form a plurality of openings 500 exposing many parts of the silicon-containing layer 53 . In this embodiment, the exposed portions of the silicon-containing layer 53 are then exposed to the energy source 52 by covering the patterned gate electrode layer 55 and melting it into a liquid at a number of predetermined locations. Preferably, an energy source 52 (eg, Nd:YAG laser, carbon dioxide (CO ₂ ) laser, argon (Ar) laser, or excimer laser) passes through the openings 500 and melts the exposed portions of the silicon-containing layer 53 . After being melted and crystallized, the silicon-containing layer 53 has a plurality of protruding tips 510 protruding from the surface of the silicon-containing layer 53 .

Furthermore, an anode electrode layer 57 and a phosphor layer 58 are sequentially formed to cover the top substrate 56, which may be a silicon substrate, a glass substrate, a quartz substrate, a sapphire substrate, a plastic substrate or similar substrates. The top substrate 56 is separated from the bottom substrate 50 by a predetermined distance, and will be placed together to form a complete triode device as shown in FIG. 5B . The triode-structured device utilizes the protruding tips 510 of the silicon-containing layer 53 as field emitters. When a voltage difference is applied between the cathode electrode layer 51 and the gate electrode layer 55 , electrons 59 are extracted from the cathode electrode layer 51 and accelerated toward the phosphor layer 58 .

Referring to FIGS. 6A and 6B , there are shown schematic cross-sectional schematic views of processing steps for manufacturing a triode device according to another preferred embodiment of the present invention. As shown in FIG. 6A, in this embodiment, a cathode electrode layer 61 and a silicon-containing layer 63 are sequentially deposited on a base substrate 60, which may be a silicon substrate, a glass substrate, a quartz substrate, a sapphire substrate, a plastic substrate or the like. the substrate. Preferably, the silicon-containing layer 63 is an amorphous silicon layer or a polysilicon layer doped with n-type or p-type impurities, and has a thickness ranging from about 200 Ȧ to about 8000 Ȧ. Next, the silicon-containing layer 63 is etched and patterned by etching and photolithography processes, thereby forming the silicon-containing islands 63A and 63B. In this embodiment, the silicon-containing islands 63A and 63B are then subjected to energy source 62 and melted into a liquid. Preferably, the energy source 62 is a laser beam, such as Nd:YAG laser, carbon dioxide (CO ₂ ) laser, argon (Ar) laser or excimer laser. After being melted and crystallized, the silicon-containing layer 63 has a plurality of protruding tips 610 protruding from the surface of the silicon-containing layer 63 .

Next, an insulating layer 64 and a gate electrode layer 65 are sequentially deposited on the silicon-containing layer 63 , as shown in FIG. 6B . The insulating layer 64 and the gate electrode layer 65 are etched and patterned by etching and photolithography processes, thereby forming a plurality of openings 600 exposing the protruding tips 610 of the silicon-containing layers 63A and 63B. Furthermore, an anode electrode layer 67 and a phosphor layer 68 are sequentially formed to cover the top substrate 66, which may be a silicon substrate, a glass substrate, a quartz substrate, a sapphire substrate, a plastic substrate or similar substrates. The top substrate 66 is separated from the bottom substrate 60 by a predetermined distance and placed together to form a complete triode device as shown in FIG. 6B . The triode-structured device utilizes the protruding tips 610 of the silicon-containing layer 63 as field emitters. When a voltage difference is applied between the cathode electrode layer 61 and the gate electrode layer 65 , electrons 69 are extracted from the cathode electrode layer 61 and accelerated toward the phosphor layer 68 .

The foregoing description of preferred embodiments of the invention has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise forms disclosed. Those skilled in the art can make other modifications and changes to the present invention according to the specific embodiments disclosed above. The scope of the invention is defined by the appended claims and their equivalents.

In addition, when describing representative embodiments of the present invention, the specification may present the method and/or program of the present invention in a specific order of steps. However, to the extent a method or procedure does not rely on the particular order of steps presented herein, the method or procedure should not be limited to the particular order of steps set forth. Those skilled in the art will appreciate that other sequences of steps are possible. Therefore, the specific order of steps presented in this specification should not be considered as limitations on the claims. In addition, the claims for the method and/or program of the present invention are not limited to performing their steps in the stated order, and it is easy for those skilled in the art to understand that the order can be changed and still remain within the scope of the present invention. within the spirit and scope of the invention.

Claims (22)

1. method of making field emission device is characterized in that may further comprise the steps:

(a) provide substrate;

(b) form silicon-containing layer in this substrate top; And

(c) by allowing this silicon-containing layer be subjected to the effect of energy source, in order to form a plurality of protrusion tip of protruding from the surface of this silicon-containing layer.

2. method according to claim 1 is characterized in that in step (a) and (b), further is included in the step that this silicon-containing layer below forms negative electrode layer.

3. method according to claim 2 is characterized in that further comprising following step:

(d) order forms insulating barrier and grid electrode layer on this silicon-containing layer; And

(e) this insulating barrier of patterning and this grid electrode layer are in order to the mass part in exposed these a plurality of protrusions tips.

4. method according to claim 1 is characterized in that this silicon-containing layer is the amorphous layer that doping is arranged.

5. method according to claim 1 is characterized in that this silicon-containing layer is the polycrystal layer that doping is arranged.

6. method according to claim 1 is characterized in that this energy source is the laser beam that is selected from by among the following group who forms: Nd:YAG laser, carbon dioxide (CO ₂) laser, argon (Ar) laser and excimer laser.

7. method of making field emission device is characterized in that may further comprise the steps:

(a) provide substrate;

(b) form silicon-containing layer in this substrate top; And

(c) by allowing this silicon-containing layer be subjected to the effect of patterning energy source, most advanced and sophisticated in order to form a plurality of protrusions that protrude from the surface of this silicon-containing layer.

8. method according to claim 7 is characterized in that in step (a) and (b), further is included in the step that this silicon-containing layer below forms negative electrode layer.

9. method according to claim 8 is characterized in that further comprising following step:

(d) order forms insulating barrier and grid electrode layer on this silicon-containing layer; And

(e) this insulating barrier of patterning and this grid electrode layer, most advanced and sophisticated in order to exposed these a plurality of protrusions.

10. method according to claim 7 is characterized in that this silicon-containing layer is the amorphous layer that doping is arranged.

11. method according to claim 7 is characterized in that this silicon-containing layer is the polycrystal layer that doping is arranged.

12. method according to claim 7 is characterized in that this energy source is the laser beam that is selected from by among the following group who forms: Nd:YAG laser, carbon dioxide (CO ₂) laser, argon (Ar) laser or excimer laser.

13. a method of making field emission device is characterized in that may further comprise the steps:

(a) provide substrate;

(b) form first conductor layer in this substrate top;

(c) form silicon-containing layer in this first conductor layer top;

(d) form the insulating barrier and second conductor layer in this silicon-containing layer top order;

(e) this second conductor layer of patterning and this insulating barrier are in order to exposed this silicon-containing layer; And

(f) by allowing this exposed silicon-containing layer be subjected to the effect of energy source, exposed a plurality of protrusions tip of surface protrusion of silicon-containing layer from this in order to formation.

14. method according to claim 13 is characterized in that this silicon-containing layer is the amorphous layer that doping is arranged.

15. method according to claim 13 is characterized in that this silicon-containing layer is the polycrystal layer that doping is arranged.

16. method according to claim 13 is characterized in that this energy source is the laser beam that is selected from by among the following group who forms: Nd:YAG laser, carbon dioxide (CO ₂) laser, argon (Ar) laser or excimer laser.

17. a method of making field emission device is characterized in that may further comprise the steps:

(a) provide substrate;

(b) form silicon-containing layer in this substrate top;

(c) this silicon-containing layer of patterning is in order to form a plurality of silicon island portions that contain; And

(d) by allowing these contain the effect that silicon island portion is subjected to energy source, most advanced and sophisticated in order to form a plurality of protrusions that protrude from these surfaces that contains silicon island portion.

18. method according to claim 17 is characterized in that in step (a) and (b), further is included in the step that this silicon-containing layer below forms negative electrode layer.

19. method according to claim 18 is characterized in that further comprising following step:

(e) order forms insulating barrier and grid electrode layer on this substrate; And

(f) this insulating barrier of patterning and this grid electrode layer, most advanced and sophisticated in order to exposed these a plurality of protrusions.

20. method according to claim 17 is characterized in that this silicon-containing layer is the amorphous layer that doping is arranged.

21. method according to claim 17 is characterized in that this silicon-containing layer is the polycrystal layer that doping is arranged.

22. method according to claim 17 is characterized in that this energy source is the laser beam that is selected from by among the following group who forms: Nd:YAG laser, carbon dioxide (CO ₂) laser, argon (Ar) laser or excimer laser.

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